a. Technical Field
The instant disclosure relates generally to a fuel rail assembly and more specifically to an end cap assembly for the fuel rail assembly.
b. Background Art
This background description is set forth below for the purpose of providing context only. Therefore, any aspects of this background description, to the extent that it does not otherwise qualify as prior art, is neither expressly nor impliedly admitted as prior art against the instant disclosure.
It is known to provide a fuel delivery system for use with an internal combustion engine. Such a system may include one or more fluid conduits that allow for the delivery of pressurized fuel to multiple fuel injectors. The fluid conduit (i.e., a fuel rail assembly) may include an inlet that is connected to a fuel source, for example, in some systems, an output of a high-pressure fuel pump. The fluid conduit also typically includes a plurality of outlets that are configured for mating with a corresponding fuel injector. The fluid conduit can have an opening at one or both of its longitudinal ends, which openings are covered and closed by an end cap.
Some fuel systems employ fuel rail assemblies to deliver fuel at a relatively low pressure (e.g., 3.0 bar to less than 100 bar). In such low pressure systems, a stamped metal end cap is used to provide a relatively low cost fuel rail assembly. It is known to employ higher pressure fuel systems, for example, gasoline direction injection (GDI) systems, which uses fuel pressures of about 100 bar (10 Mpa) in circa 2005, currently operate in the 150-180 bar (Mpa) range, and are expected to operate in the 200-350 bar (20-35 Mpa) range by 2018 and beyond. However, the above-mentioned stamped metal end caps are not used in such higher pressure systems because of limitations in the stamping wall thickness. In other words, there is a practical limit in the maximum thickness of the metal stock that can be stamped into an end cap. This (limited) thickness end cap is not suitable for such higher pressures. And while a machined metal end cap can be used that has the needed wall thickness for the increased fuel pressures, the machined end cap is more expensive. In addition, the gap left by the tube counter-bore that is not filled by the cap creates a stress riser for fatigue failures.
The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.